Systems and methods for protecting the cerebral vasculature

ABSTRACT

Disclosed are methods and devices for isolating all three of the left subclavian, left common carotid and brachiocephalic arteries from embolic debris that might flow through the aortic arch, via a single access point. A system may include an elongate flexible tubular sheath, having a proximal end and a distal end, and an inner member extending through the sheath and moveable relative to the sheath. A left subclavian element may be supported by the inner member. A filter membrane may be configured to isolate the aorta from the brachiocephalic, left common carotid and left subclavian arteries when the left subclavian element is expanded within the left subclavian artery and the sheath is retracted to expose the membrane. The left subclavian element may include a self expandable frame, which may carry a left subclavian filter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/395,412, filed Apr. 26, 2019, which claims the benefit of priorityunder 35 U.S.C. § 119 to U.S. Provisional Application Ser. No.62/663,117, filed Apr. 26, 2018, the entirety of which is incorporatedherein by reference.

TECHNICAL FIELD

In general, the present disclosure relates to medical devices forfiltering blood. And, more particularly, in certain embodiments, to amethod and a system of filters and deflectors for protecting thecerebral arteries from emboli, debris and the like dislodged during anendovascular or cardiac procedure.

BACKGROUND

Thromboembolic disorders, such as stroke, pulmonary embolism, peripheralthrombosis, atherosclerosis, and the like affect many people. Thesedisorders are a major cause of morbidity and mortality in the UnitedStates and throughout the world. Thromboembolic events are characterizedby an occlusion of a blood vessel. The occlusion can be caused by a clotwhich is viscoelastic (jelly-like) and comprises platelets, fibrinogen,and other clotting proteins.

Percutaneous aortic valve replacement procedures have become popular,but stroke rates related to this procedure are between four and twentypercent. During catheter delivery and valve implantation, plaque orother material may be dislodged from the vasculature and may travelthrough the carotid circulation and into the brain. When an artery isoccluded by a clot or other embolic material, tissue ischemia (lack ofoxygen and nutrients) develops. The ischemia progresses to tissueinfarction (cell death) if the occlusion persists. Infarction does notdevelop or is greatly limited if the flow of blood is reestablishedrapidly. Failure to reestablish blood-flow can lead to the loss of limb,angina pectoris, myocardial infarction, stroke, or even death.

Various surgical or endovascular techniques and medicaments to remove ordissolve obstructing material have been developed, to reestablish bloodflow. However, additional procedures may be traumatic and are bestavoided when possible. Additionally, the use of certain devices carryrisks such as the risk of dislodging foreign bodies, damaging theinterior lining of the vessel as the catheter is being manipulated,blood thinning, etc.

A variety of filtration or deflection devices have been proposed, toprevent entry of debris into the cerebral circulation. Some isolate onlythe brachiocephalic artery and left common carotid, while others mightadditionally isolate the left Subclavian but typically through the useof multiple catheters. Others are said to isolate all three arteriesleading to the cerebral circulation, from a single catheter, but thecatheter is introduced via the femoral artery and none have achievedadoption.

The need thus remains for a simple, single catheter to enableendovascular isolation of the complete cerebral circulation, preferablyfrom an access point other than the femoral artery.

SUMMARY

The present invention provides a three vessel cerebral protectioncatheter, for introduction through the brachiocephalic artery via theright radial or right brachial artery, and across the aortic arch. Adistal element of the catheter is anchored in the left subclavianartery, and a membrane is deployed such that the single catheterisolates all three of the left subclavian, left common carotid andbrachiocephalic arteries from embolic debris that might flow through theaortic arch.

In one implementation, a catheter may comprise an elongate flexibletubular sheath, having a proximal end and a distal end, and an innermember extending through the sheath and moveable relative to the sheath,and supporting a left subclavian element. A filter membrane may becarried between the inner member and the sheath, the membrane and theleft subclavian element configured to isolate the aorta from thebrachiocephalic, left common carotid and left subclavian arteries whenthe left subclavian element is expanded within the left subclavianartery and the sheath is retracted to expose the membrane. An aorticsupport hoop may be provided, configured to seal the membrane againstthe wall of the aorta.

The left subclavian element may comprise a self-expanding frame and maycarry a filter membrane which may have a conical configuration. Thecatheter may further comprise at least one pull wire for laterallydeflecting a distal steering zone on the sheath.

There is also provided a method of isolating the cerebral circulationfrom embolic debris. The method may comprise the steps of advancing acatheter through the brachiocephalic artery and into the left subclavianartery; deploying an anchor within the left subclavian artery; andretracting an outer sheath on the catheter to expose a filter extendingfrom the anchor, across the ostium to the left common carotid artery andinto the brachiocephalic artery. The filter may comprise a body, aperipheral edge and a self-expandable frame carried by at least aportion of the peripheral edge; wherein the frame brings the edge intoproximity of the wall of the aorta in response to the retracting step.The frame may be in the form of a loop.

The step of advancing a catheter may include the step of proximallyretracting a pull wire to laterally deflect a distal portion of thecatheter to enter the ostium of the left subclavian artery. The anchormay be carried by a tubular inner member, and the retracting step maycomprise retracting the outer sheath relative to the inner member toexpose the anchor. The deploying an anchor step may comprise deploying aself-expandable frame, and the self-expandable frame may carry a leftsubclavian filter.

In a first example, an embolic protection system for isolating thecerebral vasculature may comprise an elongate outer sheath, having aproximal end and a distal end, an inner member extending through a lumenof the outer sheath, a distal anchoring mechanism coupled to a distalend region of the inner member, a proximal filter membrane carriedbetween the inner member and the outer sheath, the proximal filtermembrane configured to extend from the left subclavian artery to thebrachiocephalic artery, an aortic support hoop coupled to the proximalfilter membrane and configured to seal the proximal filter membraneagainst the wall of the aorta, and a handle including a first actuationmechanism coupled to proximal end of the inner member and a secondactuation mechanism coupled to the proximal end of the outer sheath.

Alternatively or additionally to any of the examples above, in anotherexample, the distal anchoring mechanism comprise a self-expanding frame.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise a distalfilter membrane coupled to the self-expanding frame.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise a proximalbond tube coupled to a proximal filter bag termination of the proximalfilter membrane.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise an aorticring connector extending from a proximal end of the aortic ring toproximal bond tube.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise a deliverywire coupled to the tube and extending proximally to the handle.

Alternatively or additionally to any of the examples above, in anotherexample, the handle may further comprise a third actuation mechanismcoupled to a proximal end of the delivery wire.

Alternatively or additionally to any of the examples above, in anotherexample, the inner member may be slidably disposed within a lumen of theproximal bond tube.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise a distalsupport strut extending between a distal end of the aortic ring and theself-expanding frame of the distal anchoring mechanism.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise an aorticring connector extending from a proximal end of the aortic ring to aconnection tube disposed about the inner member and the aortic ringconnector, the connection tube distal to a proximal filter bagtermination of the proximal filter membrane.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise a proximalbond tube coupled to the proximal bag termination of the proximal filtermembrane and a delivery wire coupled to the proximal bond tube andextending proximally to the handle.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise an aorticring deployment wire coupled to the aortic ring connector and extendingproximally to the handle.

Alternatively or additionally to any of the examples above, in anotherexample, the outer sheath, the inner member, the delivery wire, and theaortic ring deployment wire may be individually actuatable.

Alternatively or additionally to any of the examples above, in anotherexample, a distal end region of the outer sheath may be deflectable.

Alternatively or additionally to any of the examples above, in anotherexample, a cross-sectional shape of the inner member adjacent to theproximal bond tube may be non-circular and at least a portion of theproximal bond tube may have a non-circular cross-sectional shape.

In another illustrative example, an embolic protection system forisolating the cerebral vasculature may comprise an elongate outersheath, having a proximal end and a distal end, an inner memberextending through a lumen of the outer sheath, a distal filter assemblycoupled to a distal end region of the inner member, the distal filterassembly including a self-expanding frame and a distal filter membranecoupled to the self-expanding frame, a proximal filter membrane carriedbetween the inner member and the outer sheath, the proximal filtermembrane configured to extend from the left subclavian artery to thebrachiocephalic artery, an aortic support hoop coupled to the proximalfilter membrane and configured to seal the proximal filter membraneagainst the wall of the aorta, a proximal bond tube coupled to aproximal filter bag termination of the proximal filter membrane, anaortic ring connector coupled to and extending between a proximal end ofthe aortic ring and the proximal bond tube, a delivery wire coupled toand extending proximally from the proximal bond tube, and a handleincluding a first actuation mechanism coupled to proximal end of theinner member, a second actuation mechanism coupled to the proximal endof the outer sheath, and a third actuation mechanism coupled to aproximal end of the delivery wire.

Alternatively or additionally to any of the examples above, in anotherexample, the embolic protection system may further comprise a distalanchoring structure positioned distal to the distal filter assembly.

Alternatively or additionally to any of the examples above, in anotherexample, the aortic ring connector may include a curved shape.

In another example, a method of isolating cerebral circulation fromembolic debris may comprise advancing an embolic protection systemthrough the brachiocephalic artery and into the left subclavian artery,deploying a distal anchor within the left subclavian artery, andretracting an outer sheath of the embolic protection system to expose afilter extending from the distal anchor, across the ostium to the leftcommon carotid artery and into the brachiocephalic artery.

Alternatively or additionally to any of the examples above, in anotherexample, the distal anchor may be carried by an inner member, the innermember separately actuatable from the outer sheath.

The above summary of exemplary embodiments is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIGS. 1-4 illustrate a method deploying a filter system to protect thecerebral vascular architecture.

FIG. 5A illustrates a first embodiment of a filter system.

FIG. 5B illustrates another alternative embodiment a filter system.

FIG. 6 is a partial cross-sectional view of the illustrative filtersystem of FIG. 5A, taken at line 6-6.

FIG. 7 is a cross-sectional view of the illustrative filter system ofFIG. 5A, taken at line 7-7.

FIG. 8 is a cross-sectional view of the illustrative filter system ofFIG. 5A, taken at line 8-8.

FIG. 9 illustrates another alternative embodiment a filter system.

FIG. 10 is a cross-sectional view of the illustrative filter system ofFIG. 9 , taken at line 10-10.

FIG. 11 is a partial cross-sectional view of the illustrative filtersystem of FIG. 9 , taken at line 11-11.

FIG. 12 illustrates another alternative embodiment a filter system.

FIG. 13 illustrates another alternative embodiment a filter system.

FIG. 14 is a cross-sectional view of the illustrative filter system ofFIG. 13 , taken at line 13-13.

FIG. 15 is a partial cross-sectional view of the illustrative filtersystem of FIG. 13 , taken at line 15-15.

FIG. 16 is a cross-sectional view of an alternative deployment tube;

FIG. 17 is a partial side view of the illustrative deployment tube ofFIG. 16 .

FIG. 18 is a cross-sectional view of an alternative inner member keyingsystem.

FIGS. 19-21 illustrate alternative distal anchoring mechanisms.

FIGS. 22A-22C illustrate alternative aortic ring connectorconfigurations.

FIG. 23 illustrates an alternative aortic ring connector configuration.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit aspects of the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimension ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the invention. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

The disclosure generally relates to devices and methods for filteringfluids and/or deflecting debris contained within fluids, including bodyfluids such as blood. The filtering or deflecting device can bepositioned in an artery upstream from the brain before and/or during anendovascular procedure (e.g., transcatheter aortic valve implantation(TAVI) or replacement (TAVR), transcatheter mitral valve implantation(TAMI) or replacement (TAMR), surgical aortic valve replacement (SAVR),other surgical valve repair, implantation, or replacement, cardiacablation (e.g., ablation of the pulmonary vein to treat atrialfibrillation) using a variety of energy modalities (e.g., radiofrequency (RF), energy, cryo, microwave, ultrasound), cardiac bypasssurgery (e.g., open-heart, percutaneous), transthoracic graft placementaround the aortic arch, valvuloplasty, etc.) to inhibit or preventembolic material such as debris, emboli, thrombi, etc. resulting fromentering the cerebral vasculature.

Devices and methods have been developed to filter blood flowing to theinnominate artery and the left common carotid artery, which provideabout 90% of the blood entering the cerebral vasculature. Examples areprovided in U.S. Pat. No. 8,876,796, which is herein incorporated byreference in its entirety. Certain such devices and methods leave theleft subclavian artery, and thus the left vertebral artery, whichprovides about 10% of the blood entering the cerebral vasculature,exposed to potential embolic material. Other embodiments described inU.S. Pat. No. 8,876,796 filter blood flowing to the left common carotidartery and the left subclavian artery 16. Certain such devices andmethods leave the innominate artery 12, and thus both the right commoncarotid artery 18 and the right vertebral artery 20, which provide evenabout 50% of the blood entering the cerebral vasculature, exposed topotential embolic material. Assuming perfect use and operation, eitherof these options may leave potential stroke rates as high as two to tenpercent due to exposed arteries that provide blood flow to the cerebralvasculature.

Several single-access multi-vessel embodiments of cerebral protectiondevices that can provide full cerebral protection (e.g., protecting allfour blood vessels supplying blood to the brain) with minimal archinterference are described below. The devices may be used to trap and/ordeflect particles in other blood vessels within a subject, and they canalso be used outside of the vasculature. The devices described hereinare generally adapted to be delivered percutaneously to a targetlocation within a subject but can be delivered in any suitable way andneed not be limited to minimally-invasive procedures.

FIG. 1 is a schematic view of an aortic arch 10. The aortic arch 10 isdownstream of the aortic valve 11. The aortic arch 10 typically includesthree great branch arteries: the brachiocephalic artery or innominateartery 12, the left common carotid artery 14, and the left subclavianartery 16. The innominate artery 12 branches to the right carotid artery18, then the right vertebral artery 20, and thereafter is the rightsubclavian artery 22. The right subclavian artery 22 supplies blood toand may be directly accessed from (termed right radial access) the rightarm. The left subclavian artery 16 branches to the left vertebral artery24, usually in the shoulder area. The left subclavian artery 16 suppliesblood to and may be directly accessed from (termed left radial access)the left arm.

Four of the arteries illustrated in FIG. 1 supply blood to the cerebralvasculature: (1) the left carotid artery 14 (about 40% of cerebral bloodsupply); (2) the right carotid artery 18 (about 40% of cerebral bloodsupply); (3) the right vertebral artery 20 (about 10% of cerebral bloodsupply); and (4) the left vertebral artery 24 (about 10% of cerebralblood supply). The devices and methods described herein are alsocompatible with the prevalent (27%) bovine variant.

FIG. 1 additionally illustrates an example three vessel protectionsystem 100, extending via right radial access across the top of theaortic arch and into the left subclavian artery 16. While theillustrative protection system 100 is described as introduced via rightradial access, it is contemplated that the protection system 100 mayalso be advanced via left radial access. In such an instance, theprotection system 100 may be advanced from the left subclavian arteryacross the top of the aortic arch 10 and into the innominate artery 12.

Generally, the protection system 100 may include an outer sheath 110, aninner member 118, a guidewire 102, a distal filter assembly 112 (see,for example, FIG. 2 ), and a proximal filter assembly 124 (see, forexample, FIG. 3 ). The outer sheath 110 and the inner member 118 may beguided over the guidewire 102, or along the guidewire 102 (in a rapidexchange configuration) to position a distal end of the outer sheath 110within the left subclavian artery 16. The inner member 118 may beradially inward of the outer sheath 110 and separately actuatabletherefrom (e.g., slidably disposed within a lumen of the outer sheath110). It is contemplated that the guidewire 102 may be positioned withina lumen of the inner member 118 or within a lumen of the outer sheath110, as desired. In some cases, the lumen of the inner member 118 may beconfigured to receive a 0.014″ (0.3556 millimeter) diameter guidewire102, although other diameter guidewires 102 may be used, as desired.Each of the guidewire 102, the outer sheath 110, and the inner member118 may be separately actuatable.

The protection system 100 may include a distal end region 101 and aproximal end region 103. The guidewire 102, the outer sheath 110, andthe inner member 118 may be configured to extend from the proximal endregion 103 to the distal end region 101. The proximal end region 103 maybe configured to be held and manipulated by a user such as a surgeon.The distal end region 101 may be configured to be positioned at a targetlocation such as, but not limited to, the left subclavian artery 16 (orthe innominate artery 12 for a left radial access procedure). Theproximal end region 103 may include a. 105, a control 107 such as aslider, the outer sheath 110, a port 109, an inner member translationcontrol 111, such as a knob, and a hemostasis valve control 113 such asa knob. In some embodiments, the handle 105 may include fewer or morecontrol elements than those illustrated in FIG. 1 . For example, thehandle 105 may include controls such that the inner member 118 may betranslated (e.g., distally advanced or proximally retracted) relative tothe outer sheath 110 and/or the handle 105, the outer sheath 110 can betranslated relative to the handle 105 and/or the inner member 118, theouter sheath 110 can be bent or deflected, etc. The handle 105 mayinclude other controls for translating and/or deflecting othercomponents of the system 100, as will be described herein. The proximalend region 103 may also include the inner member 118 radially inward ofthe outer sheath 110. While not explicitly shown, the proximal endregion 103 may also include a filter wire (not explicitly shown in FIG.1 ) radially inward of the outer sheath 110 (and sometimes radiallyoutward of the inner member 118). Some illustrative filter wires aredescribed in commonly assigned U.S. Pat. No. 9,566,144, the entirety ofwhich is hereby incorporated by reference.

The slider 107 can be used to translate the outer sheath 110 and/or afilter assembly (not explicitly shown in FIG. 1 ). For example, theslider 107 may proximally retract the outer sheath 110, the slider 107may distally advance the filter assembly out of the outer sheath 110, orthe slider 107 may proximally retract the outer sheath 110 and distallyadvance the filter assembly (e.g., simultaneously or serially), whichcan allow the filter assembly to radially expand, which will bedescribed in more detail herein. The slider 107 may also be configuredto have an opposite translation effect, which can allow the filterassembly to be radially collapsed (e.g., due to compression by the outersheath 110) as the filter assembly is drawn into the outer sheath 110.Other deployment systems are also possible, for example comprising gearsor other features such as helical tracks (e.g., configured to compensatefor any differential lengthening due to foreshortening of the filterassembly, configured to convert rotational motion into longitudinalmotion), a mechanical element, a pneumatic element, a hydraulic element,etc. for opening and/or closing the filter assembly. The slider 107 maybe independent of the inner member 118 such that the inner member 118 islongitudinally movable independent of the outer sheath 110 (and/or thefilter wire). The inner member translation control 111 can be used tolongitudinally translate the inner member 118, for example before,after, and/or during deployment of the filter assembly. An inner membertranslation control 111 may comprise a slider in the handle 105 (e.g.,separate from the slider 107).

A port 109 may be in fluid communication with the outer sheath 110(e.g., via a Y-shaped connector in the handle 105). The port 109 can beused to flush the device (e.g., with saline) before, during, and/orafter use, for example to remove air. The port 109 can additionally, oralternatively, be used to monitor blood pressure at the target location,for example, by connecting an arterial pressure monitoring device influid communication with a lumen of the outer sheath 110. The port 109can be also or alternatively be used to inject contrast agent, dye,thrombolytic agents such as tissue plasminogen activator (t-PA), etc.

A rotatable hemostasis valve control 113 can be used to reduce orminimize fluid loss through the protection system 100 during use. Forexample, a proximal portion and/or intermediate region of the protectionsystem may be positioned in the right subclavian artery 22 and thedirection of blood flow with respect to the system 100 will be distal toproximal, so blood may be otherwise inclined to follow the pressure dropout of the system 100. The hemostasis valve control 113 is illustratedas being rotatable, but other arrangements are also possible (e.g.,longitudinally displaceable). The hemostasis valve control 113 may beconfigured to fix relative positions of the outer sheath 110 and thefilter assembly, for example as described with respect to the hemostasisvalve in U.S. Pat. No. 8,876,796. The hemostasis valve 113 may comprise,for example, an elastomeric seal and HV nut.

To position the protection system 100 within the body, an incision maybe made in the subject's right radial artery, or alternatively the rightbrachial artery. An introducer (not explicitly shown) may be placed intothe incision and the protection system 100 inserted into the introducer.The protection system 100 may be advanced through the vasculature in adelivery configuration in which a filter assembly is collapsed orsheathed within the outer sheath 110. The outer sheath 110, inner member118, and the filter assemblies 112, 124 may be advanced over a guidewire102 to the target location. In some cases, the guidewire 102 may bepositioned at the target location and the outer sheath 110, inner member118, and the filter systems 112, 124 subsequently advanced over theguidewire 102 to the target location. In other instances, the guidewire102 and the outer sheath 110, inner member 118, and the filter systems112, 124 may be advanced substantially simultaneously with the guidewire102 leading (e.g., positioned most distal to) the outer sheath 110,inner member 118, and the filter systems 112, 124.

The delivery catheter or outer sheath 110 may have a diameter sized tonavigate the vasculature from the incision to the target location. Anouter sheath 110 sized for right radial access may have a diameter inthe range of about 6 French (F). An outer sheath 110 sized for femoralaccess may be larger, although this is not required. These are just someexamples. In some cases, the outer sheath 110 (or other components ofthe protection system 100) may include deflectable tip or anarticulatable distal tip. It is contemplated that the distal tip of theouter sheath 110 may be deflected (e.g., using the handle 105) tofacilitate navigation of the system 100 through the vasculature andcannulation of the target vessel. In some cases, the deflectable tip maybe configured to deflect by about 90°. However, the tip of the outersheath 110 may be made to deflect by less than 90 or more than 90, asdesired. As described above, the deflection may be controlled by arotating knob at the handle 105, or the control mechanism. In somecases, the outer sheath 110 may include a pre-shaped and/ornon-deflectable tip.

The left subclavian artery 16 may be cannulated through a combination ofadvancing and torqueing the catheter 110. In some cases, the leftsubclavian artery 16 may first be cannulated using the guidewire 102. Itis contemplated that in some cases, the deflection of the catheter tipmay be relaxed to advance the outer sheath 110 into the left subclavianartery 16. Once the protection system 100 (e.g., the distal end 104 ofthe outer sheath 110) has been advanced to the target location, which inthe illustrated embodiment may be the left subclavian artery 16, theouter sheath 110 may be proximally retracted to expose a distal filterassembly 112 beyond the distal end 104 of the outer sheath 110, as shownin FIG. 2 . Alternatively, or additionally, the inner member 118 may bedistally advanced to deploy the distal filter assembly 112. The distalfilter assembly 112 may be configured to deployed in the distal-mostgreat vessel relative to the location of the incision. For example, whenright radial access is used, the distal-most great vessel is the leftsubclavian artery 16. However, if left radial access is used, thedistal-most great vessel is the innominate artery 12.

Referring additionally to FIG. 2A, which illustrates an enlarged view ofthe distal filter assembly 112, the distal filter assembly 112 maycomprise a self-expanding filter assembly (e.g., comprising asuperelastic material with stress-induced martensite due to confinementin the outer sheath 110). The distal filter assembly 112 may comprise ashape-memory material configured to self-expand upon a temperaturechange (e.g., heating to body temperature). The distal filter assembly112 may comprise a shape-memory or superelastic frame 114 (e.g.,comprising a nitinol hoop) and a microporous filter element 120 (e.g.,comprising a polymer including laser-drilled holes) coupled to theframe, for example similar to the filter assemblies described in U.S.Pat. No. 8,876,796.

The frame 114 may generally provide expansion support to the filterelement 120 in the expanded state. In the expanded state, the filterelement 120 is configured to filter fluid (e.g., blood) flowing throughthe filter element 120 and to inhibit or prevent particles (e.g.,embolic material) from flowing through the filter element 120 bycapturing the particles in the filter element 120. The frame 114 mayconfigured to anchor the distal filter assembly 112 by engaging orapposing the inner walls of a lumen (e.g., blood vessel) in which thedistal filter assembly 112 is expanded. In some cases, the distal filterassembly 112 may also anchor the proximal filter assembly 124. Forexample. the distal filter assembly 112 may be a distal anchoringmechanism. The anchoring mechanism may include a filter membrane or maylack a filter membrane, as desired. As will be described in more detailherein, other anchoring mechanisms may be provided in addition to oralternatively to the distal filter assembly 112. The frame 114 maycomprise or be constructed of, for example, nickel titanium (e.g.,nitinol), nickel titanium niobium, chromium cobalt (e.g., MP35N, 35NLT),copper aluminum nickel, iron manganese silicon, silver cadmium, goldcadmium, copper tin, copper zinc, copper zinc silicon, copper zincaluminum, copper zinc tin, iron platinum, manganese copper, platinumalloys, cobalt nickel aluminum, cobalt nickel gallium, nickel irongallium, titanium palladium, nickel manganese gallium, stainless steel,combinations thereof, and the like. The frame 114 may comprise a wire(e.g., having a round (e.g., circular, elliptical) or polygonal (e.g.,square, rectangular) cross-section). For example, in some embodiments,the frame 114 may comprise a straight piece of nitinol wire shape setinto a circular or oblong hoop or hoop with one or two straight legsrunning longitudinally along or at an angle to a longitudinal axis ofthe distal filter assembly 112. The frame 114 may be coupled to asupport strut 121. If so provided, the straight legs may be on a longside of the distal filter assembly 112 and/or on a short side of thedistal filter assembly 112. The frame 114 may form a shape of an opening115 of the distal filter assembly 112. The opening 115 may be circular,elliptical, or any shape that can appropriately appose sidewalls of avessel such as the left subclavian artery 16. The distal filter assembly112 may have a generally proximally-facing opening 115. In otherembodiments, the opening 115 may be distally facing. For example, theorientation of the opening 115 may vary depending on where the accessincision is located.

The frame 114 may include a radiopaque marker such as a small coilwrapped around or coupled to the hoop to aid in visualization underfluoroscopy. In some embodiments, the frame 114 may comprise a shapeother than a hoop, for example, a spiral. In some embodiments, thedistal filter assembly 112 may not include or be substantially free of aframe.

In some embodiments, the frame 114 and the filter element 120 form anoblique truncated cone having a non-uniform or unequal length around andalong the length of the distal filter assembly 112. In such aconfiguration (e.g., along the lines of a windsock), the filter assembly112 has a larger opening 115 (upstream) diameter and a reduced ending(downstream) diameter.

The filter element 120 may include pores configured to allow blood toflow through the filter element 120, but that are small enough toinhibit prevent particles such as embolic material from passing throughthe filter element 120. The filter element 120 may comprise a filtermembrane such as a polymer (e.g., polyurethane, polytetrafluoroethylene(PTFE)) film mounted to the frame 114. The filter element 120 may have athickness between about 0.0001 inches (0.00254 millimeters) and about0.03 inches (0.76 millimeters) (e.g., no more than about 0.0001 inches(0.00254 millimeters), about 0.001 inches (0.0254 millimeters), about0.005 inches (0. millimeters), about 0.01 inches (0.254 millimeters),about 0.015 inches (0.381 millimeters), about 0.02 inches (0.51millimeters), about 0.025 inches (0.635 millimeters), about 0.03 inches(0.76 millimeters), ranges between such values, etc.).

The film may comprise a plurality of pores or holes or aperturesextending through the film. The film may be formed by weaving orbraiding filaments or membranes and the pores may be spaces between thefilaments or membranes. The filaments or membranes may comprise the samematerial or may include other materials (e.g., polymers, non-polymermaterials such as metal, alloys such as nitinol, stainless steel, etc.).The pores of the filter element 120 are configured to allow fluid (e.g.,blood) to pass through the filter element 120 and to resist the passageof embolic material that is carried by the fluid. The pores can becircular, elliptical, square, triangular, or other geometric shapes.Certain shapes such as an equilateral triangular, squares, and slots mayprovide geometric advantage, for example restricting a part larger thanan inscribed circle but providing an area for fluid flow nearly twice aslarge, making the shape more efficient in filtration verses fluidvolume. The pores may be laser drilled into or through the filterelement 120, although other methods are also possible (e.g., piercingwith microneedles, loose braiding or weaving). The pores may have alateral dimension (e.g., diameter) between about 10 micron (μm) andabout 1 mm (e.g., no more than about 10 μm, about 50 μm, about 100 μm,about μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, about400 μm, about 500 μm, about 750 μm, about 1 mm, ranges between suchvalues, etc.). Other pore sizes are also possible, for example dependingon the desired minimum size of material to be captured.

The material of the filter element 120 may comprise a smooth and/ortextured surface that is folded or contracted into the delivery state bytension or compression into a lumen. A reinforcement fabric may be addedto or embedded in the filter element 120 to accommodate stresses placedon the filter element 120 during compression. A reinforcement fabric mayreduce the stretching that may occur during deployment and/or retractionof the distal filter assembly 112. The embedded fabric may promote afolding of the filter to facilitate capture of embolic debris and enablerecapture of an elastomeric membrane. The reinforcement material couldcomprise, for example, a polymer and/or metal weave to add localizedstrength. The reinforcement material could be imbedded into the filterelement 120 to reduce thickness. For example, imbedded reinforcementmaterial could comprise a polyester weave mounted to a portion of thefilter element 120 near the longitudinal elements of the frame 114 wheretensile forces act upon the frame 114 and filter element 120 duringdeployment and retraction of the distal filter assembly 112 from theouter sheath 110.

The distal filter assembly 112 may be coupled (e.g., crimped, welded,soldered, etc.) to a distal end of a deployment wire or filter wire (notexplicitly shown) via a strut or wire 121, although this is notrequired. When both or all of the filter wire and the strut 121 areprovided, the filter wire and the strut 121 may be coupled to the innermember 118 proximal to the filter assembly 112 using a crimp mechanism119. In other embodiments, the filter wire and the strut 121 may be asingle unitary structure. The filter wire and/or strut 121 can comprisea rectangular ribbon, a round (e.g., circular, elliptical) filament, aportion of a hypotube, a braided structure (e.g., as described herein),combinations thereof, and the like. A distal filter bag termination 116or a distal end 116 of the distal filter assembly may also be coupled tothe inner member 118. In some cases, the distal end 116 may be coupledto the inner member using a nose cone 117. The nose cone 117 may bothsecure the distal end 116 of the distal filter assembly 112 and reduceinjury and/or vessel perforation during insertion of the system 100. Insome cases, the inner member 118 may reduce in diameter in the distaldirection. The diameter may be step-wise or gradual.

The distal filter assembly 112 in an expanded, unconstrained state mayhave a maximum diameter or effective diameter (e.g., if the mouth is inthe shape of an ellipse the effective diameter is the diameter of theapproximate circular opening 115 of the filter viewed from an end view)The diameter can be between about 1 mm and about 15 mm (e.g., at leastabout 2 mm, about 4 mm, about 6 mm, about 8 mm, about 10 mm or more, butgenerally less than about 15 mm or 12 mm or less depending upon theintended target vessel. In some embodiments (e.g., when the distalfilter assembly 112 is configured to be positioned in the leftsubclavian artery 16), the diameter may be between about 7 mm and about12 mm (e.g., about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11mm, about 12 mm, ranges between such values, etc.). In some embodiments(e.g., when the distal filter assembly 112 is configured to bepositioned in the left vertebral artery 24), the diameter may be betweenabout 2 mm and about 4.5 mm (e.g., about 2 mm, about 2.5 mm, about 3 mm,about 3.5 mm, about 4 mm, about 4.5 mm, ranges between such values,etc.). Other diameters d or other types of lateral dimensions are alsopossible. Different diameters can allow treatment of a selection ofsubjects having different vessel sizes.

The filter assembly 112 may have a maximum length from a proximal limitof hoop 114 to the distal end or point of convergence 116 with the innermember 118. The length can be between about 7 mm and about 50 mm (e.g.,at least about 7 mm, about 8 mm, about 10 mm, about 12 mm, 16 mm, about20 mm or more, but generally less than about 40 mm or 30 mm or 20 mm orless depending upon the intended target vessel. Other lengths are alsopossible, for example based on the diameter or effective diameter. Forexample, the length of the distal filter assembly 112 may increase asthe diameter increases, and the length of the distal filter assembly 112may decrease as the diameter decreases.

In the illustrated embodiment, as described herein, the distal filterassembly 112 comprises a self-expanding support such as hoop or frame114 which supports the open proximal end of an approximately conicalfilter membrane 120. A support strut 121 may be provided to connect thehoop 114 to a portion of the system 100 such as the inner member 118, tofacilitate resheathing of the filter assembly 112 and also to orientatethe hoop or frame 114. In the illustrated embodiment, the distal filterassembly 112 may function both to filter blood entering the leftsubclavian artery 16, and also to anchor the system as will be discussedin more detail herein.

Continued proximal actuation of the outer sheath 110 while fixing theinner member 118 relative to the handle 105 (and thus the deploymentwire and proximal bond, as will be described in more detail herein) maythen deploy the aortic arch component or proximal filter assembly 124,as shown in FIG. 3 . It is contemplated that distal end 104 of the outersheath 110 may be withdrawn into the innominate artery 12 or the rightsubclavian artery 22 to fully expose the proximal filter assembly 124.As the outer sheath 110 is withdrawn, the distal filter assembly 112remains in the left subclavian artery 16, supported by the inner member118 and helping to anchor the proximal filter assembly 124.

The proximal filter assembly 124 may include an aortic ring 126 orsupport element and a filter membrane or filter element 128. The aorticring 126 may be similar in form and function to the frame 114 of thedistal filter assembly 112, although larger in scale. Similarly, thefilter membrane 128 may be similar in form and function to the filterelement 120 described in herein. The aortic ring 126 generally providesexpansion support to the filter membrane 128 in its expandedconfiguration, while the filter membrane 128 is adapted to filter fluid,such as blood, and trap particles flowing therethrough. The aortic ring126 may include an approximately elliptical hoop of a shape memory wiresuch as nitinol. The aortic ring 126 may be configured to engage thewall of the aorta and seal against the roof of the aortic arch outsideof the ostia of all three great vessels 12, 14, 16 to isolate thecerebral vasculature. For example, the aortic ring 126 may be sized andshaped such that it extends from the ostium of the left subclavianartery 16 to the ostium of the innominate artery 12. The center 125 ofthe aortic ring 126 is open to allow blood and debris to enter thedevice 124, and the ring 126 is attached around its perimeter to thefilter membrane 128. The aortic ring 126 may be self-expanding such thatas the outer sheath 110 is proximally withdrawn, the aortic ring 126automatically expands, although this is not required. As will bedescribed in more detail herein, the aortic ring 126 may be coupled todifferent portions of the protection system 100.

Once the proximal filter assembly 124 has been deployed, the innermember 118 may be retracted to minimize intrusion into the aorta 10, asillustrated in FIG. 4 . The position of the inner member 118 may beadjusted using the control 111 at the handle 105. As will be describedin more detail herein, the mechanism coupling the proximal filter 124 tothe system 100 may be adjusted by proximally retracting or distallyadvancing the handle 105 to ensure the proximal filter 124 is fullydeployed, the aortic ring 126 is apposed to the roof of the aortic arch10, and the inner member 118 is pulled up against the roof of the aorticarch 10 to ensure that the membrane 128 is fully against the roof of thearch 10. The proximal filter assembly 124 is thus positioned to protectthe cerebral vasculature 14, 18, 20, 24 from embolic debris during anendovascular procedure such as TAVR.

Once the protection system 100 has been deployed, the TAVR, or otherindex procedure, may be performed. Once the index procedure iscontemplate, the inner member 118 may be advanced relative to the handle105 to apply tension to the proximal filter element 128 and/or thedistal filter element 120. The outer sheath 110 may then be advancedrelative to the handle 105, while fixing the position of the innermember 118 relative to the handle 105, until the proximal filterassembly 124 and the distal filter assembly 112 are fully sheathed. Theprotection system 100 may then be removed from the introducer sheath.

FIGS. 5A and 5B illustrate a first mechanism for coupling the proximalfilter assembly 124 to the protection system. In the illustratedembodiment, a proximal end 130 of the aortic ring 126 is connected to aproximal bond tube 132 with an aortic ring connector 134. The proximalbond tube 132 may be a tubular structure configured to link or coupleseveral structures of the system 100. In some cases, the structurescoupled to the proximal bond tube 132 may extend into and be coupledwithin a lumen of the proximal bond tube 132, as will be described inmore detail herein. The aortic ring connector 134 may be formed as amonolithic or unitary structure with the aortic ring 126. Alternatively,the aortic ring connector 134 may be separately formed and coupled withthe aortic ring 126. It is contemplated that the aortic ring connector134 may be formed from a nitinol wire, or other suitable material. Theproximal end region 136 of the membrane 128, or the proximal filter bagtermination 136, may also be connected to the proximal bond tube 132.

The proximal bond tube 132 may be connected to a delivery wire 138configured to extend proximally to the handle 105. The handle 105 mayinclude at least three controls (which may be sliding controls)including a control for translation of the inner member 118 relative tothe handle 105, a control for translation of the delivery catheter 110relative to the handle 105 to allow for deployment and retrieval of thefilter assemblies 112, 124, and a control for deflection of the distaltip of the delivery catheter 110. The delivery wire 138 is connected toboth the proximal bond tube 132 and the handle 105. Thus the aortic ring126 and proximal filter bag termination 136 positions are fixed relativeto the handle 105. As such, the position of the proximal bond tube 132relative to the patient's body can be moved by either advancing orretracting the handle 105. As described above, the distal filter frame114, and thus the distal end region 116 of the distal filter element 120or the distal filter bag termination 116, are connected to the innermember 118, and are advanced and retracted relative to the outer sheath110 with a first handle control 111. The steerable outer sheath ordelivery catheter 110 may be withdrawn relative to the handle 105 todeploy the device using a second handle control 107. The tip 104 of theouter sheath or delivery catheter 110 may be deflected to assist withcannulation of the left subclavian artery 16 (or the brachiocephalicartery 12) using a third handle control (not explicitly shown).

In FIG. 5A, the aortic ring connector 134 may be formed by bonding twoproximally extending sections of the wire forming the hoop of aorticring 126 to produce a single, relatively more rigid strut 134.Alternatively, as shown in FIG. 5B, the two wires 134, 135 which extendproximally from aortic ring 126 may be movable with respect to eachother. This allows the minor axis of the aortic ring 126 to self adjustto the aorta 10, as the two wires 134, 135 move towards or away fromeach other. Either an excess of membrane 128, or overlapping sections ofmembrane 128 carried by the wires 134, 135 allow continuity of themembrane 128 coverage regardless of the spacing between wires 134 and135.

FIG. 6 is a partial cross-sectional view of the illustrative system 100taken at line 6-6 of FIG. 5A. As can be seen, the proximal bond tube 132defines a lumen 133. The inner member 118 may be sliably disposed withinthe lumen 133 such that the inner member 118 is separately movable fromthe proximal bond tube 132. The proximal filter bag termination 136 maybe coupled to an inner surface of the proximal bond tube 132. However,other coupling configurations can be used, as desired. Further, thedeployment or control wire 138 may also be coupled to the proximal bond.The control wire 138 may be coupled directly to the proximal bond orindirectly coupled (e.g., with the proximal filter bag termination 136disposed therebetween), as desired. In some cases, the control wire 138and the aortic ring connector 134 may form a unitary structure. In otherembodiments, the deployment or control wire 138 and the aortic ringconnector 134 may be separate and distinct components.

FIG. 7 is a cross-sectional view of the protection system 100 taken atline 7-7 of FIG. 5A. As can be seen, the membrane 128 may be coupled tothe aortic ring 126 about its perimeter to define an opening for 125that allows blood and debris to enter the proximal filter assembly 124.The membrane 128 also forms a net that prevents debris from exiting theproximal filter assembly 124. In some cases, the aortic ring 126 may beinclude a radiopaque coil or marker to facilitate to allow the aorticring 126 to be visualized.

As described herein, a distal steering segment of steerable deliverycatheter 110 may be deflected laterally in response to manipulation of asteering control on the proximal manifold or handle 105. Referringadditionally to FIG. 8 , which illustrates a cross-sectional view of theillustrative system 100, taken at line 8-8 of FIG. 5A, in theillustrated embodiment, the sidewall of delivery catheter or outersheath 110 is provided with a pull wire lumen 144 for axially moveablyreceiving a pull wire 140 which may be proximally retracted to deflectthe distal tip laterally. A second pull wire may alternatively beprovided, such as at 180 degrees around the catheter 110 from the firstpull wire, to facilitate straightening or deflecting the catheter in asecond, opposite direction. Further, in some embodiments, the outersheath 110 may include a reinforcement braid 131, although this is notrequired.

FIG. 9 illustrates another alternative embodiment for the system ofFIGS. 1-8 . In the system 100′, the handle 105 may include at leastthree controls (which may be sliding controls) including a control fortranslation of the inner member 118 relative to the handle 105, acontrol for translation of the delivery catheter 110 relative to thehandle 105 to allow for deployment and retrieval of the filterassemblies 112, 124, and a control for deflection of the distal tip ofthe delivery catheter 110. In the system 100′, the proximal filter bagtermination 136 is connected to the proximal bond tube 132. The deliverywire 138 is also connected to the proximal bond tube 132 and the handle105, as can be seen in FIG. 11 which is a partial cross-sectional viewof the system 100′ taken at line 11-11 of FIG. 9 . Thus, movement of thehandle 105 is translated to the proximal bond tube 132. However, in theembodiment of FIG. 9 , the proximal end 130 of the aortic ring 126 isconnected to the inner member 118 via the aortic ring connectors 134,135. For example, referring to FIG. 10 , which is a partialcross-sectional view of the system 100′ taken at line 10-10 of FIG. 9 ,the aortic ring connectors 134, 135 may be coupled to the inner member118 via a connection tube 137, which may be a heat shrink tube. Thedistal end 139 of the aortic ring 126 may be coupled to the distalfilter frame 114 via a distal support strut 142. Thus, the aortic ring126, the distal filter frame 114, the distal filter membrane 120, andthe inner member 118 may all be advanced and retracted relative to thedelivery catheter or outer sheath 110 with the first control element 111in the handle 105. The steerable delivery catheter 110 may be withdrawnrelative to the handle 105 to deploy the devices 112, 124 using a secondhandle control 107. The tip of the delivery catheter 110 may bedeflected to assist with cannulation of the left subclavian artery 16(or the brachiocephalic artery 12) using a third handle control (notexplicitly shown).

FIG. 12 illustrates another alternative embodiment for the system ofFIGS. 1-8 . In the illustrative system 100″ of FIG. 12 , the handle 105may include at least three controls (which may be sliding controls)including a control for translation of the inner member 118 relative tothe handle 105, a control for translation of the delivery catheter 110relative to the handle 105 to allow for deployment and retrieval of thefilter assemblies 112, 124, and a control for deflection of the distaltip of the delivery catheter 110. The proximal filter bag termination136 is connected to the proximal bond tube 132. The delivery wire 138and the aortic ring connector 134 are also connected to the proximalbond tube 132 and the handle 105. Thus, movement of the handle 105 istranslated to the proximal bond tube 132. In the embodiment of FIG. 12 ,the distal end 139 of the aortic ring 126 may be coupled to the distalfilter frame 114 via a distal support strut 142. Thus, the proximalfilter bag termination 136, the aortic ring 126 and the distal filterframe 114 are all fixed relative to the handle 105. In other words,movement of the handle 105 is translated to the proximal bond tube 132via the delivery wire 138 and as the aortic ring 126 is coupled to theproximal bond tube 132 and the distal filter frame, the aortic ring 126and the distal filter frame 114 also move with the handle 105. Thedistal filter bag termination 116 is connected to the inner member 118and is advanced and retracted relative to the delivery catheter 110 witha first handle control 111 (e.g., via movement of the inner member 118).The steerable delivery catheter 110 may be withdrawn relative to thehandle 105 to deploy the device using a second handle control 107. Thetip of the delivery catheter 110 may be deflected to assist withcannulation of the left subclavian artery 16 (or the brachiocephalicartery 12) using a third handle control (not explicitly shown).

FIG. 13 illustrates another alternative embodiment for the system ofFIGS. 1-8 . In the illustrative system 100′″ of FIG. 13 , the proximalfilter bag termination 136 is connected to a first proximal bond tube132 and is fixed relative to the handle 105 via the deployment wire 138which is also coupled to the first proximal bond tube 132 and the handle105. The distal filter frame 114, and thus the distal filter bagtermination 116, are connected to the inner member 118. Both the distalfilter frame 114 and the distal filter bag termination 116 are advancedand retracted relative to the delivery catheter 110 with a first handlecontrol 111. The steerable delivery catheter 110 may be withdrawnrelative to the handle 105 to deploy the device 112, 124 using a secondhandle control 107. The tip of the delivery catheter 110 may bedeflected to assist with cannulation of the left subclavian artery 16(or the brachiocephalic artery 12) using a third handle control (notexplicitly shown). The proximal end 130 of the aortic ring 126 isconnected to a sliding aortic ring bond tube 143 via the aortic ringconnector 134. The second sliding bond tube 143 is also coupled to anaortic ring deployment wire 145. The second sliding bond tube 143 may beadvanced and retracted relative to the delivery catheter 110 with afourth handle control (not explicitly shown).

The handle 105 of the system 100′″ may include at least four controls(which may be sliding controls) including a control for translation ofthe inner member 118 relative to the handle 105, a control fortranslation of the delivery catheter 110 relative to the handle 105 toallow for deployment and retrieval of the filter assemblies 112, 124, acontrol for deflection of the distal tip of the delivery catheter 110,and a control for translation of the aortic ring deployment wire 145relative to handle 105. This may allow the aortic ring connector 134(and thus the aortic ring 126), the inner member 118 and the proximalbond tube 132 (and thus the proximal filter membrane 128) to all beadjusted relative to each other. This may allow the apposition of theaortic ring 126 to the roof of the aortic arch 10 to be furtheroptimized. In one technique, the position of the aortic ring connector134 may be fixed, and the position of the proximal bond tube 132 (andthus the proximal termination of the filter membrane 136), to bewithdrawn towards the handle 105. This applied tension on the proximalmembrane 128 may draw the aortic ring 126 towards the roof or the aorticarch 10, and increase the bend in the aortic ring connector 134, thusimproving apposition between the aortic ring 126 and the roof of theaortic arch 10.

FIG. 14 illustrates a cross-sectional view of the illustrative system100′″, taken at line 14-14 of FIG. 13 . In the illustrated embodiment,the sidewall of delivery catheter or outer sheath 110 is provided with apull wire lumen 144 for axially moveably receiving a pull wire 140 whichmay be proximally retracted to deflect the distal tip laterally. Asecond pull wire may alternatively be provided, such as at 180 degreesaround the catheter 110 from the first pull wire, to facilitatestraightening or deflecting the catheter in a second, oppositedirection. Further, in some embodiments, the outer sheath 110 mayinclude a reinforcement braid 131, although this is not required. Thedeployment wire 138 and the aortic ring deployment wire 145 may extendwithin the lumen of the outer sheath 110 but exterior to the innermember 118.

FIG. 15 is a cross-sectional view of the illustrative system 100′″ takenat line 15-15 of FIG. 13 . As can be seen, the proximal bond tube 132defines a lumen 133. The inner member 118 may be slidably disposedwithin the lumen 133 such that the inner member 118 is separatelymovable from the proximal bond tube 132. Further, the aortic ringdeployment wire 145 may also extend through the lumen 133 such that theaortic ring deployment wire 145 (and thus the second bond tube 143) isseparately movable from the proximal bond tube 132. The proximal filterbag termination 136 may be coupled to an inner surface of the proximalbody 132. However, other coupling configurations can be used, asdesired. Further, the deployment or control wire 138 may also be coupledto the proximal bond tube 132. The control wire 138 may be coupleddirectly to the proximal bond or indirectly coupled (e.g., with theproximal filter bag termination 136 disposed therebetween), as desired.Both the proximal bond tube 132 and the aortic ring bond tube 143 mayslide freely over (and/or relative to) the inner member 118.

In the protection systems 100, 100′, 100″, 100′″ it may be desirable forcorrect deployment, functioning and retrieval of the filter assemblies112, 124 for the rotational orientation between the delivery catheter110, the proximal bond tube 132, and the inner member 118 to becontrolled. Control of the inner member 118 (and thus the distal filterassembly 112) orientation relative to the aortic ring 126 (and thus theproximal bond tube 132) may prevent the distal filter frame 114 fromrotating relative to the aortic ring 126 and/or proximal bond tube143132, and resulting in a twist in the membrane 128 between the aorticring 126 and the distal filter assembly 112, leading to possiblerestriction of flow of blood and/or debris into the distal filterassembly 112 and thus the left subclavian artery. It may be desirable tocontrol the inner member 118 (and thus the distal filter assembly 112)and the aortic ring 126 (and thus proximal bond 132) orientationsrelative to the delivery catheter 110, and thus to the deflectiondirection of the deflectable outer sheath 110, to ensure that the device112, 124 deploys from the tip of the delivery catheter 110 in the aorticarch 10 in the correct orientation.

It is contemplated that the orientation may be controlled by fixing therotational orientation of the deployment wire 138 (and thus the proximalbond tube 132) relative to the inner member 118 at the attachment pointswithin the handle 105. If the orientation of the deployment wire 138 andthe inner member 118, where they are attached to the handle 105, arefixed, the orientation of the proximal bond tube 132 and the distalfilter assembly 112 may be controlled. However, the handle 105 may beseparated from the distal filter assembly 112 by some distance, and theconnecting inner member 118 and deployment wire 138 may twist or torquerelative to each other resulting in a misalignment of the distal filterassembly 112 to the aortic ring 126. This twisting may be reduced byreplacing the deployment wire 138 with a deployment tube 150 that runsin the annular space between the delivery catheter 110 and the innermember 118. FIG. 16 illustrates a cross-sectional view of this feature.Constructing the deployment wire from a tube 150 may have the advantagethat a tube resists torque more effectively than a wire, and may resultin better alignment between the proximal bond tube 132 and the aorticring 126 as the tube structure 150 may rotationally deflect to a lesserdegree than the wire. The tube 150 may be constructed of polymer, braidreinforced polymer, stainless steel or other metal. FIG. 17 illustratesa partial side view of an illustrative delivery tube 150 constructed ofstainless steel, nitinol or other metal hypo tube with laser cut slots152 to improve flexibility while maintaining axial and torsionalstiffness to maintain the position (axially and rotationally) of theproximal bond tube 132 relative to the handle 105.

In another illustrative embodiment, the orientation may be controlled bykeying the proximal bond tube 132 to the inner member 118 such that theproximal bond tube 132 can slide freely over the inner member 118, butcannot rotate relative to the inner member 118. For example, orientationof the proximal bond tube 132 relative to the inner member 118 may becontrolled at the proximal bond tube 132 instead of, or in addition to,at the handle 105. This may be done by creating a non-round ornon-circular profile (e.g., a non-circular cross-sectional shape) of theinner member 118 in at least the region where the proximal bond tube 132slides over the inner member 118. This profile (e.g., cross-sectionalshape) could be square, hexagonal, triangular, or other non-roundprofiles. The inner opening of the proximal bond tube 132 may beprofiled or keyed to match the cross-section of the inner member 118such that it can slide along the inner member 118, but not rotaterelative to the inner member 118. FIG. 18 illustrates a cross-sectionalview of such a keyed arrangement between the inner member 118 and atleast a portion of the proximal bond tube 132. While not explicitlyshown, when so provided, the aortic ring bond tube 143 and the innermember 118 may be similarly keyed. In some cases, the proximal bond tube132 may have a circular outer profile while the shape of the lumen iskeyed or shaped to match a shape of an outer surface of the inner member118 to limit rotation of the inner member 118.

The inner member 118 may be constructed of a polymer, a metal, acomposite, a wire, a braid reinforced polymer such as polyimide, nylon,Pebax, etc., or other suitable material. The inner member 118 may beconstructed with variable stiffness so that, for example, the distalportion is less stiff than the proximal portion. However, this is notrequired. In some embodiments, limit stops may be added to the innermember 118 to limit travel of the aortic ring connector 134, 135 (andthus the aortic ring 126) relative to the inner member 118, in both theproximal and distal directions. The inner member 118 may moves freelythrough the proximal bond tube 132. The limit stops may prevent theoperator from extending the inner member 118 to the extent that theinner member 118 would protrude out of the aortic ring 126 and/orprevent the operator from withdrawing the inner member 118 to the extentthat the distal filter assembly 112 is pulled out of correct placementin the left subclavian artery 16. By placing hard stops (e.g.,structural features extending from an outer surface of the inner member118) on the inner member 118 on either side of the proximal bond tube132, the distance that an operator can pull or push on the inner member118 can be controlled.

The proximal end 136 of the proximal filter membrane 128 may beterminated at the proximal bond tube 132. Apposition and sealing of theproximal filter membrane 128 in the brachiocephalic artery 12 may beachieved through a combination of sealing of the aortic ring 126 to theroof of the aortic arch 10, and the expansion of the filter membrane 128against the walls of the brachiocephalic artery 12 due to blood flowthrough the filter membrane 128. In alternate embodiments, a proximalfilter frame (e.g., similar in form and function to the distal filterframe 114) may be added to ensure that the filter membrane 128 opensfully in the brachiocephalic artery 12. This proximal filter frame maybe constructed to provide positive circumferential contact between themembrane 128 and the walls of the brachiocephalic artery 12 or mayfunction to ensure that the filter is open yet not circumferentiallypress the membrane 128 against the vessel walls. As with the distalfilter frame 114, the proximal filter frame may be bonded to themembrane or may freely float inside the membrane.

In some embodiments, the self-expanding distal filter frame 114 mayalternately not be bonded to the filter membrane 120 so that the distalfilter frame 114 may rotate relative to the membrane 120 to preventtwisting of the membrane but would still act to hold the membrane 120open inside the left subclavian artery 16 (or the brachiocephalic artery12). The inner member 118 may be extended past distal filter assembly112 to stabilize distal filter assembly 112. Also, the guidewire 102 maybe extended beyond the distal filter assembly 112 to stabilize thedistal filter assembly 112 in the left subclavian artery 16 and helpmaintain apposition of the filter frame to the vessel wall.

The distal filter assembly 112 is anchored in the left subclavian artery16 by the expansion of the distal filter frame 114 to stabilize thedevice during delivery of the proximal filter assembly 124.Alternatively, or additionally, this anchoring function could beperformed by an expanding anchor element that is inside of or distal tothe filter membrane 120. This could take the form of a self-expandingstent structure, expanding coil, inflatable balloon, etc. This featuremay be helpful holding the position of the filter assembly 112 and thusthe distal portion of the device when the inner member 118 is tensioned.

FIG. 19 is a first illustrative alternative distal anchoring structure160 positioned distal to the distal filter assembly 112. Aself-expanding nitinol mesh anchor 160 or similar component to help holdthe position of the distal end of the device. This nitinol mesh 160 canbe located between the distal filter assembly 112 and the tip or at thevery tip of the catheter. The mesh anchor structure 160 can also be ofany shape including but not limited to conical, cylindrical, etc.

FIG. 20 illustrates another alternative distal anchoring structureincluding an expandable balloon 170 positioned distal to the distalfilter assembly 112. In some cases, the expandable balloon 170 may belocated on one side of the inner member 118 distal to the distal filterassembly 112. When in position, the balloon 170 can be expanded to helphold the position of the distal end of the inner member 118. Placing theballoon 170 on one side of the inner member 118 may allow blood flow tocontinue along the other sides of the inner member 118.

FIG. 21 illustrates another alternative distal anchoring structureincluding one or more nitinol rings 180 that can expand after the outersheath 110 is withdrawn. These nitinol rings 180 can then help anchorthe distal end of the inner member 118 in the left subclavian artery 16.

The filter membranes 120, 128 may be constructed of laser drilled orperforated polymer membrane, woven nitinol wire mesh, other metal mesh,woven PEEK or other polymer mesh, etc. The porosity of the filtermembranes 120, 128 may be around 140 microns, however other porosities,either larger or smaller, are possible. The membrane hole pattern may beuniform, or the membrane may be perforated selectively in given regionsof the membrane 120, 128 to either allow or restrict flow in thoseselect regions to improve flow through lumens, encourage apposition,etc. The filter membrane 120, 128 may have fabric or other reinforcingor stiffening in selected areas to improve sheathing, unsheathing,folding of the membrane and apposition performance, see For example, theproximal filter membrane 128 may include is a strip of fabricreinforcement in the membrane material that extends from the point wherethe aortic ring connector 134 meets the aortic ring 126 to the proximalbond tube 132. The fabric reinforcement may prevent or reduce bunchingof the membrane 128 during resheathing, and may help the membrane 128fold in a controlled manner during sheathing.

The aortic ring 126 and/or the distal filter frame 114 may beconstructed of nitinol wire, as described herein, however they mayconstructed with other flexible materials such as polymer, stainlesssteel, a composite of multiple material, woven or braided like a cable,etc. The aortic ring 126 and/or the distal filter frame 114 may also belaser cut from a flat sheet of metal, polymer, etc. and then formed orshape set to the desired final shape.

The aortic ring 126 may be constructed such that it is stiffer or moreflexible in some section than in other. For example, if the aortic ring126 is constructed of nitinol wire, it may be selectively ground toreduce the diameter or thickness to alter stiffness to improveperformance, improve apposition, make sheathing easier, etc.

Radiopaque markers may be added to the filter frame(s) 114, the aorticring 126, the aortic ring connectors 134, 135 and/or other portions ofthe device to allow visualization under fluoroscopy. The marker may beplaced in selective locations or may be in the form of a coil placedover the entire aortic ring 126, filter hoop 114 or connector structures134, 135 as needed to help with positioning and visualization.

The aortic connector 134, 135 may be constructed of more rigid materialssuch as nitinol, stainless steel, polymer, etc., or may be constructedof more flexible materials such as suture, fabric, or other flexiblematerial that will still support tension to allow sheathing of theaortic ring but would allow improved apposition of aortic ring to theroof of the aorta. The aortic ring 126 may be constructed from a loop ofmaterial, for example nitinol wire, and thus the aortic ring connector134, 135 may be formed by the two ends of the loop, and then terminatedat the proximal bond tube 132. The mechanical characteristics of theaortic ring connector 134, 135 may be altered by many methods includingthe addition of heat shrink 190 over the wires 134, 135, as illustratedin FIG. 22A, the addition of a stiffening ribbon 192 (with or without aheat shrink layer 190), as shown illustrated in FIG. 22B, or usingmultiple layers of polymer. 190, 194 (with or without a stiffeningribbon 192), as illustrated in FIG. 22C

The aortic ring connector(s) 134, 135 may be curved or shaped to improveaortic ring apposition on the proximal edge of the brachiocephalic 12 orleft subclavian 16 artery ostia. The aortic ring connector may be formedin a curved shape (as opposed to a straight connector) may allow theaortic ring 126 to fully cover the brachiocephalic artery 12 withoutleaving a gap on the proximal edge 130.

In some embodiments, the aortic ring connector 134, 135 may improveapposition of the aortic ring 126 to the roof of the aortic arch 10 byfor including a back-bend shape FIG. 23 illustrates an aortic ringconnector 134 including curved shape that bends back on itself. Inaddition, the shape and bend of the aortic ring connector 134 may beadjustable. For example, the aortic ring connector 134 may include anadjustable tension member to allow the apposition of the aortic ring 126to the roof of the aortic arch to be adjusting and optimized followingdeployment.

While the methods and devices described herein may be susceptible tovarious modifications and alternative forms, specific examples thereofhave been shown in the drawings and are described in detail herein. Itshould be understood, however, that the inventive subject matter is notto be limited to the particular forms or methods disclosed, but, to thecontrary, covers all modifications, equivalents, and alternativesfalling within the spirit and scope of the various implementationsdescribed and the appended claims. Further, the disclosure herein of anyparticular feature, aspect, method, property, characteristic, quality,attribute, element, or the like in connection with an implementation orembodiment can be used in all other implementations or embodiments setforth herein. In any methods disclosed herein, the acts or operationscan be performed in any suitable sequence and are not necessarilylimited to any particular disclosed sequence and not be performed in theorder recited. Various operations can be described as multiple discreteoperations in turn, in a manner that can be helpful in understandingcertain embodiments; however, the order of description should not beconstrued to imply that these operations are order dependent.Additionally, the structures described herein can be embodied asintegrated components or as separate components. For purposes ofcomparing various embodiments, certain aspects and advantages of theseembodiments are described. Not necessarily all such aspects oradvantages are achieved by any particular embodiment. Thus, for example,embodiments can be carried out in a manner that achieves or optimizesone advantage or group of advantages without necessarily achieving otheradvantages or groups of advantages. The methods disclosed herein mayinclude certain actions taken by a practitioner; however, the methodscan also include any third-party instruction of those actions, eitherexpressly or by implication. For example, actions such as “deploying aself-expanding filter” include “instructing deployment of aself-expanding filter.” The ranges disclosed herein also encompass anyand all overlap, sub-ranges, and combinations thereof. Language such as“up to,” “at least,” “greater than,” “less than,” “between,” and thelike includes the number recited. Numbers preceded by a term such as“about” or “approximately” include the recited numbers and should beinterpreted based on the circumstances (e.g., as accurate as reasonablypossible under the circumstances, for example ±5%, ±10%, ±15%, etc.).For example, “about 7 mm” includes “7 mm.” Phrases preceded by a termsuch as “substantially” include the recited phrase and should beinterpreted based on the circumstances (e.g., as much as reasonablypossible under the circumstances). For example, “substantially straight”includes “straight.”

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent invention as described in the appended claims.

What is claimed is:
 1. An embolic protection system for isolating thecerebral vasculature, the system comprising: an outer sheath, having aproximal end and a distal end; an inner member extending through andslidable within a lumen of the outer sheath; a distal anchoringmechanism coupled to a distal end region of the inner member; a proximalfilter membrane carried between the inner member and the outer sheath,the proximal filter membrane extending proximally from the distalanchoring mechanism and configured to extend from the left subclavianartery to the brachiocephalic artery; an aortic ring coupled to theproximal filter membrane and configured to seal the proximal filtermembrane against the wall of the aorta; and a handle including a firstactuation mechanism coupled to a proximal end of the inner member,wherein the first actuation mechanism is configured to retract the innermember proximally relative to the proximal filter membrane, pulling theinner member up against the roof of the aortic arch.
 2. The embolicprotection system of claim 1, wherein a center of the aortic ring isopen to allow debris to enter the proximal filter membrane.
 3. Theembolic protection system of claim 1, wherein the distal anchoringmechanism includes a self-expanding frame.
 4. The embolic protectionsystem of claim 3, further comprising a distal filter membrane coupledto the self-expanding frame.
 5. The embolic protection system of claim4, wherein the distal anchoring mechanism includes an expandable anchordisposed distal of the distal filter membrane.
 6. The embolic protectionsystem of claim 5, wherein the expandable anchor includes aself-expandable nitinol mesh.
 7. The embolic protection system of claim5, wherein the expandable anchor includes a balloon.
 8. The embolicprotection system of claim 5, wherein the expandable anchor includes oneor more self-expandable rings.
 9. The embolic protection system of claim1, further comprising a proximal bond tube coupled to a proximal end ofthe proximal filter membrane.
 10. The embolic protection system of claim9, wherein the inner member is slidably disposed through a lumen of theproximal bond tube.
 11. The embolic protection system of claim 9,further comprising a connector coupling the aortic ring with theproximal bond tube.
 12. The embolic protection system of claim 11,wherein the connector and the aortic ring are a single monolithicstructure.
 13. The embolic protection system of claim 11, wherein theproximal bond tube is coupled to a delivery wire extending proximally tothe handle.
 14. The embolic protection system of claim 10, wherein across-sectional shape of the inner member adjacent to the proximal bondtube is non-circular and at least a portion of the proximal bond tubehas a non-circular cross-sectional shape such that the proximal bondtube cannot rotate relative to the inner member.
 15. An embolicprotection system for isolating the cerebral vasculature, the systemcomprising: an outer sheath, having a proximal end and a distal end; aninner member extending through and slidable within a lumen of the outersheath; a self-expanding distal filter coupled to a distal end region ofthe inner member; a proximal filter carried between the inner member andthe outer sheath, the proximal filter extending proximally from theself-expanding distal filter and configured to extend from the leftsubclavian artery to the brachiocephalic artery and self-expanding toseal against the wall of the aorta, wherein the proximal filter has acentral opening along one side configured to allow debris to enter theproximal filter from the aorta; and a handle including a first actuationmechanism coupled to a proximal end of the inner member, wherein thefirst actuation mechanism is configured to retract the inner memberproximally relative to the proximal filter, pulling the inner member upagainst the roof of the aortic arch.
 16. The embolic protection systemof claim 15, further comprising a proximal bond tube coupled to aproximal end of the proximal filter.
 17. The embolic protection systemof claim 16, wherein the proximal bond tube is configured such that theinner member is slidably disposed through a lumen of the proximal bondtube and the proximal bond tube cannot rotate relative to the innermember.
 18. The embolic protection system of claim 16, wherein theproximal bond tube is coupled to a delivery wire extending proximally tothe handle.
 19. The embolic protection system of claim 16, wherein theproximal filter includes an aortic ring and a proximal filter membrane,the aortic ring configured to seal the proximal filter membrane againstthe wall of the aorta, wherein the aortic ring is coupled to theproximal bond tube.
 20. An embolic protection system for isolating thecerebral vasculature, the system comprising: an outer sheath, having aproximal end and a distal end; an inner member extending through andslidable within a lumen of the outer sheath; a distal anchor coupled toa distal end region of the inner member; a proximal filter membranecarried between the inner member and the outer sheath, the proximalfilter membrane extending proximally from the distal anchor andconfigured to extend from the left subclavian artery to thebrachiocephalic artery; an aortic ring coupled to the proximal filtermembrane and configured to seal the proximal filter membrane against thewall of the aorta; and wherein the inner member is configured to beretractable proximally relative to the proximal filter membrane to pullthe inner member up against the roof of the aortic arch.